Buttonhole-sewing machine.



n. F. KNIGHT, BUTTONHOLE SEWING MACHINE.

APPLICATION FILED MAR. H, 19l5.

@3111,Y%U Patented Apr. 30, 1918.

LPH F, IGHT, 0F BEVERLY, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGN- JERSEY, A CORPORATION OF NEW JERSEY.

BUTTONHOLlE-SEWING MACHINE.

Specification of Letters Patent.

Patented Apr. 30, 191W.

Application filed March 11, 1915. Serial N 0. 13,552.

To all whom 2'13" may concern:

Be it known that I, RALPH F. KNIGHT, a citizen of the United States, residing at Beverly, in the county of Essex and State of lt'lassachusetts, have invented certain new and useful Improvements in Buttonhole- Sewing Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains, to make and use the same.

In sewing a series of buttonholes upon av machine of the above type the upper needle thread is usually severed above the work at the completion of a buttonhole either by the operator, or by thread severing and holding devices and the work is moved laterally to properly space it for the succeedlng buttonhole. When the upper needle thread is thus severed at the completion of a buttonhole the waste end of thread leading from the last needle hole passes down through the needle hole in the throat plate around the looper or other thread handling device below the work and up through the throat plate and last needle hole to the upper surface of the work. When the work is fed laterally by the operator to bring it into position for sewing the next buttonhole this waste end draws down around the looperand up through the throat plate, and extends from the completed buttonhole along the upper surface of the throat plate. In case the end is longer than the distance between two buttonholes, the waste end lies in or close to the pathof movement of the under needle and is frequently sewed in or partially sewed into the succeeding buttonhole in such manner that its free end passes up through the buttonhole to the upper side of the work, or may be carried up through the buttonhole to the upper side of the work whena button is passed through the buttonhole. It is the object of the pres- -.ent invention to provide means for overcoming this objection and to that end the invention contemplates providing the throat plate with a slot leading from the needle hole through the side of the throat plate so that the waste end of thread may draw from ihe completed buttonhole through the slot, instead of over, the surface of the throat plate and down through the needle hole, when the work is positioned for the succeeding buttonhole. With this construction the waste end of thread leading from the completed buttonhole is not held in, or close to the path of the under needle, and sewing in of the waste end is thus avoided.

The invention will be readily understood from an inspection of the accompanying drawings and the following detailed description of the mechanism illustrated therein.

In the drawings, Figure 1 is a vertical sectional view showing so much of a buttonhole sewing machine as is necessary to illustrate the application of the present invention thereto; and Fig. 2 is a detail perspective view showing the throat plate detached from the machine.

In the drawings the invention is illustrated as embodied in the buttonhole sewing machine-having the construction and mode of operation of the machine shown and described in Patent No. 1,063,880, June 3, 1913. ][n this machine the stitch forming mechanism comprises an upper needle 2, an under needle 4, and a cooperating looper 6. The upper needle 2 is eccentrically mounted in a reciprocating needle bar 8 carried in a rotary, ead. The under needle and looper are mounted in a rotary turret 10. The turret and head are rotated through a single revolution during the sewing of a buttonhole by mechanism fully illustrated and described in the patent referred to. The work is carried by a work clamp comprising the upper clamping arms 12 and the supporting plates 14 which are mounted upon a clamp carrier 16. During the sewing the work is fed by the clamp over the u per surface of a throat plate 18 mounte on the turret and provided with a needle hole 20 through which the upper and under needles reciprocate in forming the overseam stitches about the edge of the buttonhole.

In embodying the invention in this machine the throat plate 18 is provided with a slot 22 leading from the needle hole 20 through the side of the throat plate toward V which the work'is moved in spacing it for The waste end of thread leadin succeeding buttonholes. When the sewing mechanism is stopped at the completion 0 a buttonhole the parts are in the position indicated in Fig. 1. When the upper needle thread is severed between the needle eye and the upper surface of the work the waste end of thread leading from the last needle hole of the completed seam leads from the Work across the upper surface of the throat plate down about the looper and back up through the throat plate, and through the last needle hole. laterally to space it for the succeedin buttonhole thev waste end of thread raws around the looper and passes through the slot 22 so that it passes from the work to the looper through the slot 22 instead of over the surface of the throat plate and is free to drop away from the looper, or to be carried back away from the needle hole by the backward movement of the looper at the beginning of the next sewing operation. from the completed buttonhole on the un or side of the work is not, therefore, retained in or near the path of the under needle and there is practically no danger that this thread will be carried up through the succeeding buttonhole slit or be sewed into the seamin such manner that it will be forced up through the slit when a button is passed through it. I

While it is preferred to employ the specific constructlon and arrangement shown and described it will be understood that this construction and arrangement is not essential except so far as specified in the claims and may be varied and modified without departing therefrom.

Having explained the nature and object of the invention and specifically described one form of mechanism in which it may be embodied, what is claimed is 1. A buttonhole sewing machine, having in combination, an u per needle and cooperatin] thread han ling devices, and a threat p ate having1 a needle hole and a slot leading from t e needle hole through the side of the throat plate and arranged to register with the thread leading from the When the work is moved end of the seam to the needle hole when the work is moved in spacing the buttonholes.

2. A buttonhole sewing machine,having in combination, stitch forming mechanism comprising upper and under needles and a cooperating looper, a throat plate provided with a needle hole and with a slot leading from the needle hole through the side of the throat. plate and arranged to register with the upper needle thread leading from the end of the seam to the looper when the work is moved'to space the buttonholes.

3. A buttonhole sewing machine, having in combination, stitch forming mechanism comprising an upper needle, and an under needle whlch passes'up through the buttonhole slit,-a throat plate having a needle hole through which the needles -reciprocate and having a slot leadin from the needle hole through the side? 0 the throat plate toward which the work is moved in spacing the buttonholes.

. 4. A buttonhole sewing machine, having in combination, sewing mechanism comprising an upper needle and cooperating thread handling devices and a work clamp relatively movable to sew about a buttonhole, and a throat plate having a slot leadin from the needle hole through the side 0 the throat plate and arran ed to register with the upper needle threa leading from the end of the seam to the thread handling devices when the work is moved to space the buttonholes.

5. A buttonhole sewing machine, having, in combination, a rotary sewing mechanism comprising an upper needle, an under needle and an under looper and a work clamp relatively movable to sew about a buttonhole, a

- throat plate. rotating with the sewing mechholes.

- RALPH F. KNIGHT. Witnesses:

CHESTER E. Rooms, Annm L. FREAK. 

